meanpc:
The discussion is about WiFi.
Yes, I know. So the RFXduino Linux gateway system allows (for example) an Uno to create a TCP/IP link over a wireless nRF24L01+ connection. You can implement a web server on the Arduino, send emails, even send Tweets via an SSL connection (which you can't do with a standard WiFI/Ethernet shield.)
So what part of WiFi functionality are you out missing on here? It's actually conceptually very similar the Yun gateway, except you have a central shared Linux server, rather than one strapped to every Arduino. Hence the cost efficiencies!
Put the hardware where you need it, rather than redundantly (and expensively) replicating it.
And that's the point of this thread, yes?